Elevator-control system



E. B. THURSTON ELEVATOR CONTROL SYSTEM Feb. 28, 1928. 1,661,020

Filed Dec. 10, 1921 DEVICES IN'VEN'IE 'AITEIRNEY Patented as, 1928.

UNI ED STATES PATENT OFFICE.

' hoisting drum 7 passes over id nmms'r 1B. rnolisfron, or routine, OHIO, ASSIGNOR To run nAUon'roN ELEVATOR &

HACEINEYGOMPANY, OF TOLEDO, OHIO, A CORPORATION OF OHIO.

ELEVATOR-CONTROL SYSTEM.

Application flled necember 10, 1921. Serial No. 521,533.

This invention relates to the control of electric equipment.

This invention has utility in connectlon with the operation of a driven member in limited regions, as,in a terminal region for making an elevator move to. a landing where the limit or other switch may interfere with normal stopping.

Referring to the drawing: I

The figure is a wiring diagram of an em bodiment of the invention in connection with an alternating current three phase motor circuit for elevator operation and control.

The phase alternating current motor 1 is shown as having shaft 2 carrying bralge drum 3 normally set by spring 4. This motor shaft 2 has worm 5 thereon for speed reduction driving of worm wheel 6.actua-ting drum 7 carrying cable 8 to elevator car 9 for causing said elevator car travel as to landings 10 in elevator shaft 11. This elevator hoisting cable 8 extending past the or 12 to counterwei ht 13. I

In the e evator car 9 is a remote control device for o crating the motor 1. This remote contro apparatus or controller 14 has contact 15 engagin medial terminal 16 having line 16 extending to power supply line 17. By shifting the controller 14 for updirection travel of the elevator car 9 in the elevator shaft 11, such contact 1 5 of the controller will move over to contact 18 in communication by line 19, with normally closed upper final or stopping switch 20, thence by line 21 to energize coil 22 of up direction switch 23, thence by line 24 through safety devices such as car door interlock,

landing door interlock, over-travel switches, etc., thence by line 25 to power supply line 26, thereby completin a phase for energizing this coil 22 and closing up-direction switch 23.

Power may be supplied from the line 17 through this switch 23 by way of line 27 to coil 28 of the slow speed winding of the motor 1. This line 27 has branch 29 to'coil 30 of slow speed main switch 31, thence by line 32 through interlock 33 at main high speed switch 34. This interlock 33 is closed when such high s eed switch 34 is open. From this interloc 33 the current is conducted by, lines 35, 36, to the up-direction switch 23 which by way of line 37 is connected with the supply line 26. Accordingly, simultaneously with the energizing of the up-direction switch 23 there is energlzing of slow speed main switch 31.

This main slowswitch 31 is connected back of the direction switch 23 which'has l ne 38 therefrom to this switch 23 and there connected to line 39, through resistances 40, 41, 42, and line 43 to coil 44 in the slow speed primary winding of the motor 1. Third power supply line 45 is connected by-this slow speed main switch 31 with line 46' throughresistances 47, 48, 49, and thence by line 50 m connection with coil 51, thereby completing the three connections to the coils 28, 44, 51, of the slow speed windin of the motor 1, and energizing such win ing for slow speed'operation of'the motor 1 with all the resistances in series.

Simultaneously with this energizing of the motor 1 for slow speed operation, the brake drum 3 is released. From the line 38 extends line- 53, to brake coil 54 operable against the action of thespring 4 to release the drum 3, thence by lines 55, 56, to the line 27.

Upon the closing of the direction switch and throwing in of the main slow speed sw tch, there also occurs operation of a third switch. The line 39 has branch line 57 to 0011 58 of slow speed acceleration switch 59, thence by line 60 to the line 46; As this switch 59 is closed, line 61 from the line 57, 1S connected to line 62, cutting out the reslstance 40, and also, line 63 from the line 60 1s connected to line 64 cutting out the resistance 47. The cuttin down of the resistance in starting accor ingly has a slight mechanical lag behind the closing of the main slow speed switch 23.

The controller 14 may now be shifted to have its contact 15 upon terminal 65, as desired to speed up the motor 1 from the slow I vi -c; neeinao automatically cuts out the slow speed winding coils 28,'4ll, 51. fiimultaneously the power supply line d5 throu nected with line 78 and hig speed winding coil 75. i

The power line 38 has branch 76 to the switch 34:, which from thence extends by line 77 to coil 78 out the high speed winding oft-he motor 1. The line 56 is connected to the third coil 79. Accordingly the three coils 75, 78, 79, of the high speed primary winding of the motor 1 are now energized. In normal operation of the motor 1 the controller 1% may be thrown so that this high speed winding is in at once at startin without the intermediate low speed. thus obtained greater starting torque than on the slow speed normal acceleration.

With the motor under way in operation oil the high speed windin 75, 78, 79, further shifting of the controller 1% to contact 80 I brings no results, for line 81 therefrom is to interlock 82 held open by the throwing ot the main high speed switch 34: into operative position. However, if a switch be open, say the slowing down limit switch 67, this main high speed switch coil 70 is ole-energized and the switch 34 is accordingly opened, bringing the interlock 2 down into contact position for line 81. When this switch 34: is de-energized by the opening of (37, this does not de-energize or preclude complete current for the coil at the slow speed main switch 31.. Accordingly, in throwing this switch 87 say by travel of the car 9 past such switch there is merely deenergizing of the coils 75, 78, 79, ot the high speed winding ot'the motor 1. lit the controller 14 be lettih control position up to and including the terminal 65, the motor 1 may be operated upon the slow speed winding 28, at, 51.

The torque of the slow speed winding is less than that of the high speed winding and With a heavy load upon the elevator ear 9 it may not be possible to shift the load say to get an exact landing position, while the winding 28, 4A, 51, has resistances in series therewith for the desired normal acceleration and control. However, this diliiculty may be cured by shitting of the controller 14 to contact 80 which, through the line 81 and the interlock 82 ma have connection by line 83 to energize coil 84 of switch 85. The line 88 from this coil 84 extends to the line 71 connected through the safety devices for completing the circuit of the coil 84 at the switch 85.

Throwing of this switch 85 connects line 87 between resistances 48, 49, with line 88 connected to the line 64, thereby cutting out the resistances 47, 48, of the slow speed winding. Simultaneously, line 89 between resistances 4:1, 42, is connected by way of line 90 to the line 62, thereby cutting out the h line 72 is con-,

T iere is the switch resistances 40, t1. this substantial reduction in the resistance of the slow speed winding for this motor 1, there is such proortional increase in the torque that the oad which the elevator car may be designed to handle, may be taken care of for the short distance of travel as desired in the limit stop region as effectively by the low speed winding as by the high s eed winding, while.

preserving the desired eatures of control in other operation of the car. .This control is determined by the position of the car in the region of a limit, and therefore is independent of the car speed but has to do with car position. The operation as described for the updirection travel correspondingly applies in down-direction travel by shifting of this controller 1 The windings 28, at, 51, are accordingly of one speed or low speed for the motor 1, and the windings 75, 78, 79, are accordingly for a second or higher speed of the motor 1. The brake coil at is operative, regardless of which winding is in for driving. Y

ll or availing of advantages in electromagnetic or generator action in stopping the car, the operator may hold the controller ll'so that its contact 15 is over at least as far as contact 65 when the car is within the region of the slow-down switch 87 but had not opened the final limit switch 20. Tt the tor action of braking the controller should not be further over than the terminal 18. There is, accordingly, within the control of the operator of the car a generator action braking in stopping the car due to the interlock on the open high speed switch interlock 33 on the main hi h speed switch. This interlock 33 not on y closes the slow speed switch 31 but keeps'resistance in series with the slow speed winding so that the slow speed winding is, loaded. Accordingly, as long as the motor 1 rotates above the syn chi'onous speed of the windings 28, 4d, 51, there is a little magnetic braking or loadin resisting the operation of such motor 1 and this action is independent of the operation of the spring 4 on the brake drum 8, for as long as the controller 14 is in position to permit this loading of the motor 1 by the winding 28, 4t, 51, the brake coil 54 18 energized. For final stopping of the motor 1, it is in order to throw the controller 14 to central or 0d position.

What is claimed and it is desired to secure by Letters Patent is: i

1. An elevator, a motor therefor having low and high speed windings, resistance in series with the low speed winding, cut out means for the high speed winding and a controller provided with connections extending to eoact difierently as to resistance for til too

low speed winding motor acceleration when the high speed winding is cut out by said means than. when said cut-out means is in.

2. An elevator, a motor therefor having a low speed primary winding and a high speed winding, resistance in series with the low speed primar winding, cut out means for the high spee winding, and connections for chan mg the resistance to increase the low spee winding torque when the cut out means has operated, said connections including a controller shiftable to control nerator braking action of the low speed winding. 3. In electrical power equipment, a controller, a motor, a set of switches and resistances for automatically bringing the motor through a series of speeds in timed sequence into a predetermined final speed, and another switc for putting the motor into a different final speed, the actuation of said last mentioned switch operatin to automatically return said set of switc es to initial position.

4. In electrical powerequipment, a controller, a motor having a pluralit of windin s which will operate at a uralitz'y of di erent speeds, a set of switc es an resistances controlled thereby associated with one of said windings, and control circuits operative to position said switches in a predetermined initial condition when the controller is not in the position for actuating connected.

6. An elevator, a motor therefor, a resistance for the motor, slow down and stop limit switches for the elevator, a controller on the elevator for the motor, a slow down switch device, and connections from-the controller, rendered effective by the .elevator openin said slow down switch, for coaction throng said device for cutting said resistance in or out at will while the motor is still connected.

7. An elevator, a motor therefor, a resistance for the motor, a stop switch, a slow down limitswitch directly adjacentthereto to be operated by elevator travel, a controller on the elevator for the motor, the normal control of the motor by the controller being limited to a restricted range of controller operation by the limit switch, and a resistance connection device, said device being rendered operative by the opening of said slow down switch by the elevator, and said device being controllable by the movement of said controller beyond its restricted normal range to cut in or cut out said resistance at will.

8. An elevator, an alternating current motor for actuating the elevator, said motor having a plurality of synchronous speeds, a limit switch controlled by the position of the elevator, a controller, connections from the controller normally available to cause I the motor to approach its lowest synchronous speed, and other connections from the controller, rendered available by the operation of the limit switch, for increasing the tendenc of the motor to approach its lowest sync ronous s eed during the travel of the car beyond and away from the point where the limit switch is operated.

9. A two speed alternating current electric motor, a current supply for said motor,

control connections for high and low synchronous speed operation of the motor, a limit switch device for cutting out the high speed motor connection, a resistor in the low speed motor connection, and a controller operablefindependently of motor speed and effective at will, when the high speed motor operation connection is cut out by said switch device, to lessen the' effect of the resistor in the low s eed motor connection during further trave in the same direction.

10. A polyphase alternatin current electric motor provided with a lbw speed primary winding and a high speed winding, control connections for the windings, resistance in series with the low speed connection having a portion thereof maintained in circuit when the motor is normally operating at low speed, a limit switch for cutting out the hi h speed winding, and a controller shiftable. to a position normally bringing about high speed operation of the motor, but effective by operation of the limit switch and for continued operation in the same direction, to reduce the resistance in series with the low speed winding.

11. A multi-speed alternating current motor, control connections for varying the speed of the motor, a limit switch device for cutting out high speed operation of the motor through said connections, means for modifying the current flow through the motor, and a controller'shiftable to a position.

where it is effective, by operation of the limit switch and for continued operation in the same direction, to chan e the current flow modifying means in the ow speed motor operation connection to increase the'tendency to approach lower synchronous speed of the motor.

12. An elevator, an alternating current motor therefor having high and low synchronous speed windin s, a limit safety cut out for the high spee winding resistance coacting with the low speed windin and having a. portion thereof maintained in circuit when the motor is normally operating "for we winfiinp; a limit safety device euitemeticsfiy operable by elevates tseve e defiei'mined fangs fez? entering em; seid. high speed Winding, e resist-wee 'm 1' Blew speed winclimg having s; pussies. theses)? msimsimeel in eimuit when she meter is eesmelli eperstimgse flew speed sesistenee being efieetive in me ee? ste ping :Ees leeci erstwepemtieze eff seid moses izm'gemesstisg" emrent beck inte seid emsem supply sndl eenibrefies, preeimdled by said eonnectiens medifiyimg s35 61 sesisztence when she high spec-,6. in-meg in, but efieesive *iahreugh said eenmeetiens, when lewiee em sue the speed "med gs fleeing seidi sesiseeeee sheseby she sisssfing theme-s @m. flew speed mem fez sensing the meters is eppmseh flewer synehrenees speed hsedfing fine Med 03 the GEEVWZUK,

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